1) Emotions consist of physiological responses, feelings, and behaviors that work together. They help mobilize energy for dealing with important situations. 2) The amygdala plays a key role in processing fear and other emotions. It detects emotionally arousing stimuli and coordinates behavioral and physiological responses. 3) Serotonin and prefrontal cortex activity help regulate aggression levels. Low serotonin is associated with more aggression.

1. Emotions

2. Emotions
• Emotions consist of patterns of physiological
responses and species typical behaviors
• In humans these responses are accompanied
by feelings
• Feelings + appropriate behavior = Emotions

4. Emotions as response patterns
• an emotions responses consists of three types
of components
1. Behavioral components
2. Autonomic responses
3. Hormonal responses

5. Behavioral components
• The behavioral component consists of muscular
movements that are appropriate to the situation
that elicits them
• For example, a dog defending its territory against
an intruder first adopts an aggressive posture ,
growls, and shows its teeth
• If the intruders do not leave, the defender runs
toward it and attacks

7. Autonomic responses
• Autonomic responses facilitate the behaviors and
provide quick mobilization of energy for vigorous
movement
• The activity of the sympathetic branch increase
while that of the parasympathetic branch
decreases
• As a consequence, the heart rate increases, and
change in the size of blood vessels shunt the
circulation of blood away from the digestive
organs toward the muscles

9. Hormonal responses
• Hormonal responses reinforce the autonomic
responses
• The hormones secretes by the adrenal medulla,
epinephrine and nor epinephrine , increase
blood flow to the muscles and cause nutrients
stored in the muscles to be convert into glucose
• The adrenal cortex secretes steroids hormones,
which also help to make glucose available to the
muscles

11. Categories of emotions

12. Fear
• The integration of the components of fear
appears to be controlled by the amygdala
• Location: The amygdala is located within the
temporal lobes
• Functions: It play a special role in physiological
and behavioral reactions to objects and situations
that have special biological significance, such as
those that warn of pain or other unpleasant
consequences or signify the presence of food,
water, salt, potential mates or rivals, or infants in
need of care

14. Fear
 The amydala has been divided into approximately twelve regions
 Various nuclei of the amygdala become active when emotionally relevant
stimuli are presented
 Major regions of the amygdala
• Medial nucleus – receives sensory input, including info about the
presence of odors, and relays it to the medial basal forebrain and
hypothalamus
• Lateral nucleus (LA) – receives sensory info from the primary
somatosensory cortex, association Cortex, thalamus and hippocampus
formation; sends projections to basal, accessory basal, and central
nucleus of the amygdala
• Central nucleus (CE) – region of the amygdala that receives sensory info
from the basal, lateral, and accessory basal nuclei and projects to a wide
variety of regions in the brain; involved in emotional responses;
• The CE project to regions of the hypothalamus, midbrain, pons , and
medulla that are responsible for the various component of emotional
responses

16. Aversive stimuli
• The central nucleus of the amygdala is the single most
important part of brain for the expression of emotional
responses provoked by aversive stimulus.
• When threatening stimuli are presented, both the neural
activity of the central nucleus and the production of FOS
protein increase.
• Conditioned emotional response – a classically conditioned response that
occurs when a neutral stimulus (e.g. bell) is followed by an aversive
stimulus (e.g. shock); usually included autonomic, behavioral, and
endocrine components such as changes in heart rate, freezing, and
secretion of stress-related hormones
• However, if an organism can learn a coping response (a response that
terminates, avoids, or minimizes an aversive stimulus), the emotional
responses will not occur
• CE necessary for development of a conditioned emotional response

17. Damage to the central nucleus
• Damage to central nucleus( or to the nuclei that
provide it with sensory information) reduce or
abolishes a wide range of emotional behaviors
and physiological responses
• After damage, animals no longer show sign of
fear when confronted with stimuli that have been
paired with aversive events
• Ledoux and his colleagues have shown that the
central nucleus is necessary for the development
of a conditioned emotional response
• If this nucleus is destroyed, conditioning does not
take place

18. Research with human
• Lesion of the amygdala decrease people’s
emotional responses.
• Studies: Two studies found that people with
lesions of the amygdala showed impaired
acquisition of a conditioned emotional
response, just as rats do
• Effects on memory: Damage to the amygdala
also interferes with the effects of emotions on
memory
• Studies : Mori et al.(1999) questioned patients
with Alzheimer’s disease who had witnessed

19. Cont…
the devastating earthquake that struck Kobe ,
Japan, in 1955
• They found that memory of this frightening
events was inversely correlated with amygdala
damage
• The more a patient’s amygdala was degenerated,
the less likely it was that the patient
remembered the earthquake

20. Amygdala activity toward emotional
responses
• Several imaging studies have shown that the human
amygdala participates in emotional responses
• Cahill et al.(1996) had people watch both neutral and
emotionally arousing films( such as scenes of violent
crime)
• Later, the experimenters placed the subjects in a PET
scanner and asked them to recall the film
• The activity of the right amygdala increased while
the subject recalled the emotionally arousing films
but not when they recalled the neutral ones

22. Anger and aggression
• Species-typical behaviors
• Many related to reproduction (e.g. gain access to mate)
• Threat behaviors – a stereotypical species-typical behavior
that warns another animal that it may be attacked if it does
not flee or show a submissive behavior; displayed more often
than actual attacks
• Defensive behaviors – a species-typical behavior by which an
animal defends itself against the threat of another animal
• Submissive behaviors – a stereotyped behavior shown by an
animal in response to threat behavior by another animal;
serves to prevent an attack
• Predation – attack of one animal directed at an individual of
another species on which the attacking animals normally
preys

23. Neural control of aggressive behavior
• Periaqueductal grey matter: The PAG of the
mid brain appears to be involved in defensive
behavior and predation. These mechanisms
are modulated by the hypothalamus and
amygdala

24. Role of serotonin
• Several studies have found that serotonergic
neurons play an inhibitory role in human
aggression
• A depressed rate of serotonin release ( indicated
by low levels of 5-HIAA in the CSF) are associated
with aggression and other forms of antisocial
behavior, including assault, arson, murder, and
child beating
• Coccaro et al. (1994) studied a group of men with
personality disorder(including history of
impulsive aggression) with the lowest
serotonergic activity

26. Treatment
• If low level of serotonin release contribute to
aggression, drugs that act as serotonin
agonists might help to reduce antisocial
behavior
• Coccaro and kavoussi(1997) found that
Fluoxetine (Prozac), a serotonin agonist,
decreased irritability and aggressiveness, as
measured by a psychological test

28. Orbit frontal cortex
• Location: It is located at the base of the
frontal lobes and covers the part of the brain
just above the orbits( the bones that form the
eye sockets hence the term orbito frontal
• Its inputs provide it with info about what is
happening in the env’t and what plans are
being made by the rest of the frontal lobes,
and its outputs permit it to affect a variety of
behaviors and physiological responses

31. Prefrontal cortex
• The prefrontal cortex plays an important role
in regulation of emotional expression,
including anger and aggression
• In a laboratory setting, anger activates this
region
• Violent criminals generally show a low level of
activity of this region, and the volume of gray
matter in this region was lower than normal in
a group of people with antisocial personality
disorder

32. Role of serotonin
• The release of serotonin in the prefrontal
cortex activates this region, and some
investigators believe that the serotonergic
input to this region is responsible for the
ability of serotonin to inhibit aggression and
risky behavior
• Low 5-HIAA low level of serotonin low
activity in prefrontal cortex high level of
aggression

34. Communication of emotions
How to communicate emotions

35. Means of communication of emotions

37. 2) Facial expressions

38. 3) Non verbal sounds

39. Facial expression of emotions

40. Innate responses
By CHARLES DARWIN

41. CHARLES DARWIN

42. CHARLES DARWIN AND EMOTIONS
• Human expressions of emotions evolved from
similar expressions in other animals.
• Emotional expressions are innate, unlearned
responses consisting of a complex set of
movements , principally of the facial muscles.

43. Charles Darwin
• Obtained evidence by observing his own
children.
• Also studied across culture
• Words used may be different because of
developing different languages but the
emotional expressions are the same.
• People in different cultures used the same
pattern of movements of facial muscles to
express a particular emotional state.

45. research
• By EKMAN and his colleagues
• Confirm Darwin hypothesis that facial
expressions of emotions uses an innate,
species typical repertoire of movements of
facial expressions.
• Studied an isolated tribe in new guinea

48. research
• Conclusion:
expressions were unlearned behavioral
patterns.
Different cultures use different words but
the facial expressions are the same.
words must be learned and not innate.

49. research
• Compared the facial expressions of blind and
normally sighted children.
• If expressions of two groups are similar than
the expressions are natural and do not require
learning by imitation.
• Results confirmed the naturalness of
expressions.

50. Neural basis of communication of
emotions

51. Communication a two way process

52. research
• By kraut and johnston
unobtrusively measured people in
circumstances that would be likely to make
them happy.
Only small signs of happiness when alone but
more happiness when interacting with other.
Even 10 month infants showed this tendency.

54. Emotional recognition and brain
• Right hemisphere plays an important role in
comprehension of emotions.
• High activity of pre frontal cortex
• Comprehension of emotion only by tone of
voice increased the right pre frontal cortex
activity

55. Pure word deafness
• Caused by damage to the left temporal cortex
• The man could not comprehend the meaning
of speech but had no difficulty identifying the
emotions being expressed by its intonation.

56. Role of amygdala in emotional
recognition
• Role in emotional responses
• Role in emotional recognition
• Lesions of the amygdala impair peoples ability
to recognize facial expressions of emotions,
esp. expression of fear.
• High activity of amygdala in cases of fear
• Only small increases in case of happiness

57. Continued…
• Lesions don’t appear to affect people’s ability to
recognize emotions in tone of voice.
• Amygdala receives visual info that we use to
recognize facial expressions of emotions directly
from the thalamus and not from the visual
association cortex.
• Amygdala receives visual info from two sources:
• 1) sub cortical
• 2) cortical

58. Cont….
• The superior colliculus and pulvinar( a large
nucleus in the posterior thalamus) gives input
to the sub cortical and because of this even
some people with blindness caused by
damage to the visual cortex can recognize
facial expressions.

60. IMITATION

61. Role of imitation
• Somatosensory cortex
When we see some one making an expression,
we imagine our own self making the same
expression.

62. Moebius syndrome

63. Cont….
• Defective development of 6th and 7th cranial
nerves and results in facial paralysis and inability
to make lateral eye movements.
• Bec of this defect cannot make facial expressions
of emotions.
• Difficulty in recognizing the facial expressions of
other people
• Their inability to produce facial expression of
emotions makes it impossible for them to imitate
the expression of other people.

64. DISGUST

65. CONT…
• Damage to the insular cortex and basal ganglia
• Expression of disgust activates the insular
cortex
• The insula contains the primary gustatory
cortex, so it is also involved in recognition of
bad taste.